Yet another slow 3288

[trek71]

Dear Fellow Boaters,

First of all, I have to mention that I did quite a research/reading in the forums regarding speed issues and made myself a bit smarter on wider trim tabs, longer drop fins, weight distribution, max rpm without load etc.

I hope to hear other creative ideas about this specific case

So, I have a '90 3288 with twin 150HP water cooled turbo Hino's. (Engine hour 4800)

There is some confusion, whether these are 135HP or 150HP because the manual mentions both, but the engine code is W04C-T.

Facts:

-Purchased the boat 4 months ago. At the sea-trial the boat did 15knots (nautical miles) at WOT. Bottom of the boat had some growth by that time.

-I did another sea trial 1 month after purchasing and we reached about 14knots at WOT. The bottom was already cleaned by the diver with a sponge.

-Max RPM at WOT was 2700 (according to tachs, but they are probably not that accurate). The play weird at times due to possible grounding issues.

-Previous owner had installed new propellers, he had no clue about the specs but I am sure they are a bit larger in diameter & pitch. I roughly measured 17.5 inch diameter during a haul-out

-Boat hauled-out, bottom cleaning and fresh antifouling paint. The old paint was not sanded-off, instead a primer coat was applied on top of the existing paint + 2 new coats.

-A new 180Ah battery (about 50kg) added to the aft battery bank, sits next to the transom between two engines.

-Oil change, filters change, cleaning of strainers, water separator check, brand new impellers

-We started our 500 miles trip to the destination. That was about 10 hours of uninterrupted run of engines. We found out that we could reach 10knots at WOT. So we travelled with 8-9 knots at 2400rpm.most of time.

-After 3 days and 250miles, both turbos gave up. Max RPM was about 2000 without turbos. Massive black smoke over 1800RPM.

-Stopped for maintenance: installed brand new injectors (all 8), port turbo revised, strbrd turbo brand new (old one was beyond repair), fuel pumps examined & changed all gaskets and seals. Strbrd cylinder head gasket changed. Manicoolers pipes chemically cleaned.

-The only thing we didn't is to measure the compression of the engine.

-There is not much additional weight on the boat, I placed some stuff into the locked under the fwd berth.

After all this max RPM without load (transmission neutral) is at 3400rpm; speed is barely 11knots at WOT at 2800RPM.

And we cannot get the boat to planing, which is very frustrating. We are basically getting burried into the water. Test was done with virtually empty water tank and 2/3 fuel on both tanks. Meanwhile I discovered that the behavior is independent of water/fuel level.

-and yes, 4 trim tabs are functional (brand is: Bennet)

Is there anything that I should be focusing now?

Thanks a lot!

[Pcpete]

How frustrating! Im guessing when you did your sea trial it was before loading your personal belongings aboard. It's surprising how much weight that can add, and, depending on where it is loaded, how it can mess with performance. That the boat, reading between the lines of your narrative, has slowed since your purchase as you loaded it points toward the props being too "tall". The other thing I can think of is old or poor quality fuel. Even though you have added new fuel to the boat, it may be that it isn't burning well. Sort of like the difference between regular and premium gasoline. An analysis of the fuel may be a worthwhile look.

[trek71]

Hi Pete,

Thanks for the reply.

Well we can take fuel out of the equation because we tanked several times since then and we always tank by the most reputable brand here.

Regarding weight, it is really so minimal. We added some minimal dishware stored in the kitchenette and the majority is paper-based disposable stuff. (Don't prefer dish washing in caravan & boat).

Then there is some clothing in the aft state room + some spare parts, which should account for 50-60kg (that is about 30 pounds, I guess) and definitely not more.

The only big difference is that new battery accounting for 50kg. Ok- that is placed towards the stern as far as possible so the net effect would be really bigger, but for God's sake, that is not more than skinny woman sitting on the transom!

I will definitely take out all the weight we added and do another trial, however it doesn't make sense to me...

Is there maybe a magic screw on these Hinos's, maybe we turn it either way for 2 degrees and we are back in game?

[Guest]

Wow, the 150 hino should max out at 3000 rpm. 3400 sounds dangerous or possibly the tachs are way out. My buddy and I both have 1990 3288s his is faster than mine. Who knows why.. weight ,props, tuning. But we average the similar cruising speeds. 12-13.5 knots at 2500 rpm. I hit 18 knots at wot untill recently.. one motor is 300-500 rpm slower(by ear, the tachs are out) at wot! This mystery is still not solved. He sent a pic of his gps at 21 knots, that was flying through active pass on a push tide lol. Just for reference.

There is no way those motors should reach 3400 rpm. That's a recipe for disaster, short pulls at 3000 rpm. Run all day at 2700 rpm or less no worries.

I would address the over revving issue first.. could be a tranny issue, but very weird to have the same problem in both trannys. Do you notice a higher fuel burn in one motor? Do you feel a pull to one side ?

Best of luck, watch those rpms.

I love my 3288, best mistake we ever made.

Onging problems.

Mystery head smell.

One engine slower..

Buddy has mystery overheating problem.. he's changed everything.

[trek71]

Well, that 3400 RPM is while the transmission is on neutral.

My understanding is that the recommended max RPM on neutral is 3200. I had read in Hino manual that the engine should not exceed 3400 RPM with neutral transmission.

Actually the guy who checked/revised the fuel pump had originally set it to max at 3200. He said he did it according to specs of this particular model of pump. I don't know what he was referring to but having read about the 3400, I asked him to slightly increase the setting.

Maybe that was wrong, but it should be still within the limits. I think I can talk to him to reset that to his original setting, but I'm sure that is not the problem (might lead to a slight increase in fuel consumption, though).

My gut feeling is that we cannot get the required torque out of the engines..However, all being the same (that is same propeller, same load) + a cleaner hull + nearly overhauled engines, cannot understand that performance figure.

Apart from playing with the weight distro, I'm considering to install new propellers according to stock specs (or anything recommended here based on experience).

Owners reported here different propellers from 16 up to 17 inch with varying pitches and cups, so I'm quite confused what specs to follow. e.g. what are your prop specs?

The other thing I'm considering is to digitalize the instruments...Cannot invest too much on that one, but considering a nice Arduino project for couple of bucks. That would solve the Tacho issue.

However, all this is just trial & error...I'm hoping for someone to come up with a hammer and hit the right spot!

[floatyerboat]

As much as I hate to admit it I'm a freak for things running perfect but I also know my limitations and would not hesitate to take it to a expert and have him or her have a look under the hood.

[Jim_Gandee]

Trek,

How are you measuring your speed, is that a GPS speed? Have you added any drag producing extras i.e. FB enclosure?

Things to ck on the engines:

Unrestricted air intake and flow throughout and including the exhaust risers, hoses and mufflers

Turbos rotate free with no drag, no scoring of blades or housing

No air intake leaks between compressor section of turbo and engine

Proper compression

Fuel injection timing

Unrestricted fuel flow and access to engines- read clean filters and no lines with separated inner walls (aneurysms)

Proper valve clearance

Smoke? Color?

If you have aftercoolers double ck they are not clogged and restricting air flow.

There's more but these are the easy to ck items and I bet you'll discover the cause. Of course you have verified the RPMs with a digital tach. Let us know what you find.

[mister_larry]

I would suggest you delay any experiments with props until you get the mechanical issue resolved. Your deterioration in performance is not going to be fixed with a new prop.

Your boat slowed down during the first month of ownership, and cruised at 14Knots with engines turning at 2700 RPM when you started your cruise. Then you had the break down, had it fixed and your next trip was with engines delivering 2800 RPM for a speed of 11K. What's going on? It's not the props. Gooeyduck Joe can get 13.5K at 2500 with his tired engines. Use that as a target. He is most likely on plane then (or at 2700) and can put the trim tabs down.

Then refer to Jim Gandee's list. Fuel and air is all that makes the diesel run. It's supposed to get a lot of air all the time, then add fuel to that air charge. Guarantee that cool, fresh air gets into the engine, but NO AIR in the fuel line. Did all fuel lines get tightened after the latest round of work? FYI, they do make more aggressive turbo wheels to use in the compressor, but that is for later. Back to Jim's list, the fuel needs to get there in sufficient quantities, and on time. And it needs to exhaust.

If all exhaust can't leave the combustion chambers, carbon build up can be a big-time problem and result in even higher compression ratios and early combustion. Read severe loss of power here. I doubt this event would transpire in the short time you have owned the boat, but an inspection of the combustion chambers would verify carbon build-up. Did you watch when they changed the head gasket? If not, talk with the mechanic that did the job.

Something mechanical is happening and FWIW I think you should address that problem before you tinker with props.

[smitty477]

trek71,

You mentioned you are not sure if the tachs are accurate - have you confirmed that yet with a strobe tach?

You are concerned about props - what props do you have exactly? Pitch X diameter X # blades and condition and material?

Are the props completely clean and without any damage (even minor) since sea trail?

What are the boost numbers on your new and recon turbos? (psi)

Why did you replace the turbos? ( elbow leaks?)

When you purchased the boat was it in dry storage just prior?

By any chance have you had the boat weighed on a lift?

How low does the boat sit with the boot stripe and stern compared to other 32'S?

[dlbhaas]

We're the props changed after the sea trial? If they were are they the correct props?

[Nikko]

Just FYI ..

my port tach reads approx. 100 rpm slower than stbd

I scaled at 18,000 lbs last time out (wet boat loaded with our stuff)

Some days I can reach 3000 rpm right off the bat , others I can reach 27/2800 RPM and it then the thing creeps up and up sometimes to 3000,others to 2900 - but I have aftercoolers, so I think I can attribute the difference to water temperature (boat is faster in winter than summer)..

I pin at 3000 RPM in neutral and throttles firewalled

Totally agree that 3400 is not good at all. should be fixed quickly..

Agree with "run 2700 RPM all day"..and do..

I've tracked my"mystery head smell" to a permeated holding tank - through the judicious use of No-flex digester and trying hard to keep the tank aerobic I can live with it this summer, but it's on top of the winter project list to replace..

Last o'heat issue was an oyster in the raw water intake.. Loads of fun to break up when the boat is in the water and you're in the engine compartment opening the seacock, smash smash smash - close the seacock, pump the bilge and repeat..

Sounds like original poster is over-propped and under-trimmed.. I have 17x17.5" (4-blade) wheels and they're oversize - they cause cavitation damage on the leading edge of the tunnel, there's no way I could run a bigger diameter.. Not sure about your boat(s), but mine's happy at 6-7 knots, not happy up to about 14 knots (2500 rpm ish), and then seems to give it's head a shake and take off after that.. I've got 200' chain and 2 Gp 31's up front - the boat can be over-trimmed if the tabs are all the way down when I'm on the coal.. Maybe a day of a weight transfer experimenting is in order?

"Gooeyduck Joe" post=818207 wrote:
Wow, the 150 hino should max out at 3000 rpm. 3400 sounds dangerous or possibly the tachs are way out. My buddy and I both have 1990 3288s his is faster than mine. Who knows why.. weight ,props, tuning. But we average the similar cruising speeds. 12-13.5 knots at 2500 rpm. I hit 18 knots at wot untill recently.. one motor is 300-500 rpm slower(by ear, the tachs are out) at wot! This mystery is still not solved. He sent a pic of his gps at 21 knots, that was flying through active pass on a push tide lol. Just for reference.

There is no way those motors should reach 3400 rpm. That's a recipe for disaster, short pulls at 3000 rpm. Run all day at 2700 rpm or less no worries.

I would address the over revving issue first.. could be a tranny issue, but very weird to have the same problem in both trannys. Do you notice a higher fuel burn in one motor? Do you feel a pull to one side ?

Best of luck, watch those rpms.

I love my 3288, best mistake we ever made.

Onging problems.

Mystery head smell.

One engine slower..

Buddy has mystery overheating problem.. he's changed everything.

[smitty477]

Hello Nikko,

"I pin at 3000 RPM in neutral and throttles firewalled

Totally agree that 3400 is not good at all. should be fixed quickly..

Agree with "run 2700 RPM all day"..and do"

I do not agree with your assessment or advice - .

- You need to set up the engines so that they can see 3,300 in neutral and 3,400 is fine

Just do it slow on a warmed up engine and it will be fine

- You can only run at 2700 'all day' safely if your engines can hit at least 3,000 on that day , better yet reaching 3090 - 3150.

- If your high idle (neutral rpm) is set for 3000 exactly that engine will never see 3,000 when in gear The governor droop is alt least 60 rpm and more typically a bit higher and that translates to 120 rpm at the crank. That is why it is important to set high idle to at least 3200-3300 but best on the high side.

Hope this helps

[Guest]

So you did 15kts at 2700rpm before, now 11kts at 2800. Doesn't sound like an engine problem unless your tacos are now reading differently than before.

Does the boat dig a hole in the water and sit there? That's what mine did when I lost a trim tab. I know you said you have all 4 and they are working, but what you are describing sounds like a trim tab problem or some type of drag. or somehow the rpms from the engine aren't being transmitted to the water, such as a transmission or prop, but that would be very obvious.

If you have large props at 2800rpm you should be on top of the water, no doubt. I run 14kts at 2960rpm but with 15.5" pitch. I also had to extend my tabs.

I would check the tabs again. Maybe try to get a helper and visually look down at the tabs while running WOT. You should be able to see if the tabs are down.

[trek71]

Dear All

Thank you so much for your contribution.

I was on a business trip to the Saudi Desert (not much of fun in July), hence my late reply.

I hired a captain (who happens to be an ex-military marine diesel engine mechanic). The same guy who did the initial oil/filter/impeller etc. change.

The boat is now on her way to the permanent mooring harbor. Will take about 4 days to cover 300nm at 8knot @2000rpm.

I will wait for the captain's analysis after the trip to get the facts and share the details here for your kind consultation.

Meanwhile I talked to the mechanic who has done with turbo/injector changes.

Mechanic says, there are no issues with the engine itself:

-he checked the valve clearance

-he checked the injection timing (but not necessarily as per the procedure described in the manual, as I understand);

------on that topic he says "a wrong injection timing would lead to several symptoms like smoke, engine not starting right away, continue to run after hitting the kill switch, weird running behavior"

-he checked the cylinder and block, no sign of any carbon build-up, extremely clean. I should actually have a photo of the cylinders, they looked quite clean

-he did not check the compression

------on that topic he says "if compression were low, we should be seeing oil leakage here and there e.g. on exhaust, turbo. So his deduction is "no compression issue"

My engineer mind says that these are the potential areas where the root cause stem from:

-engine

-transmission (Hurth)

-shaft/engine alignment

-propeller

-trim tab

Unless the captain reports other facts on this 300nm journey, the engine seems to be vetted as per the mechanic's explanation.

I asked whether the transmission could be a problem (e.g. worn clutch/plates etc.) which would lead to lower rpm at shaft compared to the engine. The mechanic said "if that would be the case, we should also see a much higher rpm when transmission is engaged, e.g. something around 3100 - 3200, because the load from the propeller would not be transmitted to the engine. We see some 2700-2800 at WOT so that wouldn't be the case That explanation made sense to me.

The mechanic thinks it's either the propeller (bent etc.) or trim tab or both.

I agree with dpeery regarding potential trim tab problem; or rather I hope that it's the trim tabs as this can be easily rectified.

I couldn't measure the propeller size as this is a cumbersome procedure. I know that it measured roughly 17'' in diameter; not sure about the pitch. And no cavitation damage was visible around prop pockets.

Trim tabs seems to be ok in shape but it could be possible that the oil pressure is somewhat low and tabs cannot hold their position under water pressure and giving in. Not sure how to check the pressure, though.

In the end the bow goes up and playing with the trim tabs have a little affect on the bow.

the strobe tach is a brilliant idea! seems to be an expensive gear, though...

[trek71]

Adding some pictures.

the old antifouling paint was orange. we did the 14-15knots in this condition.

New paint is black and props were brushed for cleaning...Can such a prop cleaning lead to bends etc?


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